<i>In vitro</i> and <i>in vivo</i> evaluation of a novel polymer-free everolimus-eluting stent by nitrogen-doped titanium dioxide film deposition

Park, Dae Sung,Bae, In-Ho,Jeong, Myung Ho,Lim, Kyung Seob,Sim, Doo Sun,Hong, Young Joon,Lee, So-Youn,Jang, Eun Jae,Shim, Jae-Won,Park, Jun-Kyu,Lim, Han Chul,Kim, Han Byul Elsevier 2018 Materials Science and Engineering C Vol.91 No.-

<P><B>Abstract</B></P> <P>Inflammation and thrombosis are linked to the use of polymer-based drug-eluting stents (DES). The aim of this study was to develop a polymer-free everolimus (EVL)-eluting stent using nitrogen-doped titanium dioxide (N-TiO<SUB>2</SUB>) and verify its efficacy by <I>in vitro</I> and <I>in vivo</I> assessment in a porcine coronary model. Various analytical approaches such as scanning electron microscopy and atomic force microscopy, electron spectroscopy, Fourier transform infrared spectrometry and contact angle measurement were employed for the characterization. As a part of biocompatibility assessment, platelet adhesion and smooth muscle cell (SMC) proliferation were examined. Bare metal stent (BMS), N-TiO<SUB>2</SUB> stent, everolimus-eluting N-TiO<SUB>2</SUB> (N-TiO<SUB>2</SUB>-EVL) stent, and commercialized EVL-eluting stent (EES) were randomly placed in forty coronary arteries in twenty pigs. After four weeks of implantation, the stents were subjected to histological and quantitative analysis. The N-TiO<SUB>2</SUB> film used in this study was well coated without any cracks or peeling. Surface hydrophilicity (88.8% of angle decrement) could be associated with the decrease in surface roughness post N-TiO<SUB>2</SUB> deposition (37.0%). The platelet adhesion on the N-TiO<SUB>2</SUB> surfaces was less than that on the BMS surface. The proliferation of SMC was suppressed in the N-TiO<SUB>2</SUB>-EVL group (30.2%) but not in the BMS group. In the animal study, the percent area restenosis was significantly decreased in the N-TiO<SUB>2</SUB>-EVL group compared to that in the BMS group. The results (BMS; 47.0 ± 11.00%, N-TiO<SUB>2</SUB>-EVL; 31.7 ± 10.50%, and EES; 29.1 ± 11.21%, <I>n</I> = 10, <I>p</I> < 0.05) were almost at par with those of the commercialized EVL-eluting stent. The introduction of N-TiO<SUB>2</SUB> deposition during fabrication of polymer-free DES may be an efficient accessorial process for preventing in-stent restenosis and thrombosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N-TiO<SUB>2</SUB> surfaces can help to reduce the platelet adhesion. </LI> <LI> In porcine model, N-TiO<SUB>2</SUB> everolimus decreased in-stent restenosis and fibrin deposition. </LI> </UL> </P>

Transfer of ultrathin molybdenum disulfide and transparent nanomesh electrode onto silicon for efficient heterojunction solar cells

Kang, Sung Bun,Kwon, Ki Chang,Choi, Kyoung Soon,Lee, Rochelle,Hong, Kootak,Suh, Jun Min,Im, Min Ji,Sanger, Amit,Choi, In Young,Kim, Soo Young,Shin, Jae Cheol,Jang, Ho Won,Choi, Kyoung Jin Elsevier 2018 Nano energy Vol.50 No.-

<P><B>Abstract</B></P> <P>Two-dimensional transition-metal dichalcogenides (TMDCs) are very promising for photovoltaic (PV) applications due to their excellent light absorption properties and appropriate bandgap energy, Although multifunctional applications of TMDCs in photovoltaic devices have been achieved, the photovoltaic conversion efficiency under 1 sun is still very low with small active area because of their inexpedient high sheet resistance and limitation of synthesis techniques. In this study, we demonstrate uniform synthesis of 4-in. wafer-scale MoS<SUB>2</SUB> thin films by thermal decomposition of solution precursors. The solar cells are fabricated by transferring n-MoS<SUB>2</SUB> thin films on p-Si substrates to form p-n heterojunctions and then transferring Au nanomeshes prepared in a novel surface treatment as transparent top electrodes onto MoS<SUB>2</SUB>. The circular n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell exhibited a power conversion efficiency of 5.96% at a diameter of 0.3 in. and proved to be easily scalable to 1-in. diameter with 5.18% efficiency. To the best of our knowledge, the solar cells of this study are the most efficient and the largest in all types of solar cells based on TMDC reported so far. Finally, based on finite difference time-domain simulation, we proposed a strategy for implementing n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell with efficiency higher than 15% by introducing optimal doping control of n-MoS<SUB>2</SUB> and efficient anti-reflection layers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The large scale, uniform (4-in.) MoS<SUB>2</SUB> thin films are synthesized. </LI> <LI> High transparent, low sheet resistances electrodes are fabricated in a novel way. </LI> <LI> The efficient MoS<SUB>2</SUB> based solar cells are developed by all transfer process including top electrodes. </LI> <LI> The highest, largest MoS<SUB>2</SUB> p-Si/ heterojunction solar cells are demonstrated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P> <B>The highest performance (5.96%), largest area (1 in.) n-MoS2/p-Si solar cells with transparent electrodes fabricated by a novel way.</B> The transparent electrodes lowers the series resistance of the fabricated solar cells, facilitating the collection of photo-generated carriers from the junction. In our knowledge, we have achieved the highest photovoltaic performance at largest active area by using transparent nanomesh electrode among TMDC based solar cells.</P> <P>[DISPLAY OMISSION]</P>

공군사관생도의 심폐능력에 따른 심리 · 생리요인 비교

김인기(In-ki Kim),김건희(Gun-hee Kim),송성우(Sung-woo Song),최가람(Ga-ram Choi),엄장원(Jang-won Eom),곽재준(Jae-jun Kwak),유영남(Young-nam You),정덕화(Deok-hwa Jeong),강지훈(Ji-hun Kang) 육군사관학교 화랑대연구소 2019 한국군사학논집 Vol.75 No.2

The purpose of this study was to analyze the differences in psychological and physiological factors between groups by classifying groups based on the 3km running record of fourth grade Air Force Academy cadets. Among the top 46 Air Force Academy cadets who wanted to participate in the study, the study conducted an open survey of the top 13 and the bottom 15 who wanted to provide the data prior to the study. The subjects of the experiment and in-depth interview were studied by a total of 18 people, 9 of each upper and lower members who wished to participate in the study. Psychological factors were structured through inductive content analysis of data extracted from in-depth interviews, and physiological factors were conducted to verify differences between groups of body composition and cardiopulmonary function. The psychological factors of the upper and lower groups were found to be general areas of performance strategy, achievement motivation, emotional response, military spirit, situation perception, and basic physical strength. In the detailed areas, the subjects were also examined in 15 areas including physical fitness indicators, confidence, condition control, task orientation, and positive self-perception. As a result of comparison between upper and lower groups, the upper group was 2.2 times higher than the lower group and the lower group was 1.7 times higher than the upper group in the military spirit and performance strategy of the general area response rate. In general area response, the ratio of mental strength and confidence was different in the general area of military spirit. In addition, the upper group in the achievement motivation showed a high percentage of task tendency at 47%, while the lower group showed a high rate of zero motivation at 50%. In the emotional response, the upper group showed an equal ratio, while the lower group showed an 81% ratio of negative emotions. In the overall response by sub-region, the negative emotions of the subgroup were high at 28%. In the body composition, BFM showed a statistically significant difference between upper and lower groups, and Weight, FFM, and SMM did not show any significant difference between groups. In cardiopulmonary capacity, VO2max showed a statistically significant difference between upper and lower groups, and VE and LT did not show significant differences between groups.

폐쇄형 소셜 네트워크 서비스 애플리케이션 사용성 평가 연구

장성희(Jang, Sung Hee),김승인(Kim, Seung In) 한국디지털디자인협의회 2014 디지털디자인학연구 Vol.14 No.1

최근 모바일 소셜 네트워크의 지속적인 성장과 시장의 확대로 인해 그 형태 또한 사용자의 특성과 욕구에 따라 다양하게 출시되고 있다. 그 중 제한된 인원으로 그룹을 생성해 유대감을 형성하는 폐쇄형 소셜 네트워크가 지속적 성장 가능성을 보이고 있다. 본 연구에서는 이러한 폐쇄형 소셜 네트워크에 해당하는 네이버의 밴드와 카카오의 카카오그룹의 각 특성을 분석하여 지속적인 이용자 확보와 서비스 개선을 도모하는데 목적이 있다. 연구방법으로 우선 1차로 문헌연구를 통해 각 서비스들에 대한 이해를 바탕으로 이론적인 토대를 구축하고 2차로는 사용자 경험측정을 위한 태스크 설계 및 인뎁스 인터뷰(In-depth interview)와 피터모빌(Peter Morville)의 허니콤모델(Honey Comb Model)을 재구성하여 연구를 진행하였다. 연구결과, 밴드의 경우 다양한 기능으로 그룹간 깊은 유대감을 형성하는데 도움이 되는 점에 만족성을 보였다. 그러나 기능들의 일관적인 구성이 필요하였다. 카카오 그룹의 경우 사용자들 대부분이 디자인적인 항목과 접근성에 만족도를 보였다. 그러나 대부분의 실험자들이 지속적인 모임의 형태를 갖추기에는 기능에 관한 추가적인 보완이 필요하다고 느꼈다. 마지막으로 두 서비스 모두 특정인원과 유대감을 형성하는 서비스인 만큼 현실에서의 모임이 모바일을 통해 이루어질 수 있는 추가적인 기능들이 보완되길 원했다. 본 연구를 바탕으로 향후 폐쇄형 소셜 네트워크 서비스의 사용성을 통해 진행된 추가 연구와 가이드라인이 다양하게 제시되길 기대한다. Due to the continuous growth of mobile Social Network Service and expansion of market size, those types are diversely changed and released according to the users’ characteristics and needs. Among those types, closed-type social network which creates a group with limited members and forms a sense of fellowship shows a continuous growth potential. This study has an objective to secure the consistent users and improve the services by analyzing ‘Naver band’ of Naver and ‘Kakao Group’ of Kakao which are closed-type social network. As research methods, first, theoretical foundation was constructed based on the understanding about the individual services through literature studies and secondly, the research was conducted by reorganizing the task design, in-depth interview and Honey Comb Model by Peter Morville to measure the users’ experiences and subsequently, the relevant indicators and standards were established. Study results showed test subjects were satisfied in the regards that ‘Naver Band’ creates a deep sense of fellowship with specific group due to various functions for the users. However, it was necessary that the menu composition should be simply divided in order to help the users understand in the execution process of various functions. Most users in Kakao Group showed high satisfaction with design categories and easy-to-use functions. However, most test subjects felt additional compensation is required to have the form of consistent meetings. Finally, most of test subjects wanted security related functions to be added because both services of Naver Band and Kakao Group have closed characteristics. Based on this study, additional studies and guidelines which are based on the utilization of closed-type social network service are expected to be added in the future.

Functional characterization of MATE2-K genetic variants and their effects on metformin pharmacokinetics

Chung, Jae-Yong,Cho, Sung Kweon,Kim, Tae Hee,Kim, Kyoung Hee,Jang, Geun Hye,Kim, Choon Ok,Park, Eun-Mi,Cho, Joo-Youn,Jang, In-Jin,Choi, Ji Ha Wolters Kluwer Health | Lippincott Williams Wilkin 2013 Pharmacogenetics and genomics Vol.23 No.7

OBJECTIVE: Human multidrug and toxin extrusion member 2 (MATE2-K, SLC47A2) plays an important role in the renal elimination of various clinical drugs including the antidiabetic drug metformin. The goal of this study was to characterize genetic variants of MATE2-K and determine their association with the pharmacokinetics of metformin. METHODS: We screened DNA samples from 48 healthy Koreans for variants in the promoter and coding regions of MATE2-K and examined the function of common haplotypes in the promoter region using in-vitro luciferase assays. Then, the metformin pharmacokinetic study was carried out to determine the association between MATE2-K promoter haplotypes and metformin pharmacokinetics. RESULTS: Nine variants in the promoter region of MATE2-K and one nonsynonymous variant, p.G211V, were identified. The MATE2-K promoter haplotype 1 containing a known functional polymorphism, g.−130G>A and haplotype 2 containing two polymorphisms, g.−609G>A and g.−396G>A showed a significant increase in reporter activity. Among the 45 individuals who participated in the metformin pharmacokinetic study, 12 healthy Koreans who were homozygous for haplotype 1 or 2 showed a significant increase in renal clearance [539±76 (reference group) vs. 633±102 (variant group) ml/min; P=0.006] and secretion clearance [439±81 (reference group) vs. 531±102 (variant group) ml/min; P=0.007] of metformin compared with that shown by the reference group. CONCLUSION: Our study suggests that common promoter haplotypes of MATE2-K are associated with the pharmacokinetics of metformin.

GR-tree: 무선 센서 네트워크에서 에너지 효율적인 분산 공간색인기법

김민수,장인성,Kim, Min-Soo,Jang, In-Sung 한국공간정보학회 2011 한국공간정보학회지 Vol.19 No.5

최근 특정 공간영역 내에 포함되는 센서노드들만의 센싱정보를 에너지 효율적으로 수집하는 센서 네트워크 기반 공간질의처리에 대한 관심이 증가하고 있다. 이러한 센서 네트워크 기반 공간질의처리의 가장 단순한 방법은 모든 센서노드의 위치와 센싱정보를 서버로 수집한 다음, 서버에서 공간질의를 처리하는 Centralized 방법이다. 이 방법은 간단하다는 장점은 있지만, 모든 센서노드를 접근하기 위하여 소요되는 높은 무선통신 비용으로 인하여 센서노드의 에너지 효율성이 크게 떨어지는 단점을 가지고 있다. 이러한 Centralized 방법을 보완하기 위하여 센서노드에서 분산 공간 필터링을 수행하여 센서노드 간의 무선통신 횟수를 감소시키는 In-network 기반 분산 공간색인기법들이 제안되어 왔다. 그러나, 이러한 분산 공간색인기법들은 대부분 서버에서 이용되던 기존 공간색인기법들을 센서 네트워크에 단순히 적용하였기 때문에, In-network 환경에서 공간 필터링의 효과와 센서노드들 간의 무선 라우팅을 동시에 최적화하지 못하는 단점을 가지고 있다. 이에 본 논문에서는 In-network 환경에서 공간 필터링을 최적화하면서 동시에 센서노드들 간의 라우팅을 보장할 수 있는 GR-tree의 새로운 분산 공간색인기법을 제안하고자 한다. GR-tree 방법은 R-tree와 유사하게 MBR 기반의 트리를 구성하며, 센서노드들 간의 무선 라우팅 및 공간적인 인접성을 보장하면서 MBR들 간의 겹침을 최소화할 수 있는 특징을 가지고 있다. 끝으로, GR-tree와 기존 방법들의 다양한 성능 비교 실험을 통하여 제안된 방법의 효율성을 보여주고자 한다. Recently, there has been much interest in the spatial query which energy-efficiently acquires sensor readings from sensor nodes inside specified geographical area of interests. The centralized approach which performs the spatial query at a server after acquiring all sensor readings, though simple, it incurs high wireless transmission cost in accessing all sensor nodes. In order to remove the high wireless transmission cost, various in-network spatial indexing schemes have been proposed. They have focused on reducing the transmission cost by performing distributed spatial filtering on sensor nodes. However, these in-network spatial indexing schemes have a problem which cannot optimize both the spatial filtering and the wireless routing among sensor nodes, because these schemes have been developed by simply applying the existing spatial indexing schemes into the in-network environment. Therefore, we propose a new distributed spatial indexing scheme of the GR-tree. The GR-tree which form s a MBR-based tree structure, can reduce the wireless transmission cost by optimizing both the efficient spatial filtering and the wireless routing. Finally, we compare the existing spatial indexing scheme through extensive experiments and clarify our approach's distinguished features.

Evaluation of ion implantation for anti-thrombogenic coronary stent in vitro and in vivo

Shim, Jae-Won,Bae, In-Ho,Park, Dae Sung,Lim, Kyung-Seob,Lee, So-Youn,Jang, Eun-Jae,Park, Jun-Kyu,Kim, Ju Han,Jeong, Myung Ho Elsevier 2017 Journal of industrial and engineering chemistry Vol.54 No.-

<P><B>Abstract</B></P> <P>The aim of this study was to evaluate the effect of ion implantation on the surface of anti-thrombogenic coronary stent. Nitrogen (N) was implanted into the cobalt–chromium surface by using an ion source under a plasma environment to enhance its hardness and surface modification. The N ion dosage was 1×10<SUP>15</SUP> ions/cm<SUP>2</SUP>. All analysis results of the ion implanted stent were compared with those of bare metal stent. The N component and distribution were confirmed by auger electron spectroscopy. Microhardness was significantly increased after 40min of implantation (415.3±12.38 HV, 18.9±2.62%). The surface was altered to hydrophobic status through ion implantation (30.6±1.12% in contact angle increment). Platelet adhesion, and smooth muscle cell migration and proliferation were prevented in the ion implanted group (43.9%, 11.2%, and 45.1%, respectively). To verify the in vitro result, stents were implanted to rabbit iliac artery and isolated at 4 weeks post implantation. Then, the stents were subjected to histological analysis. No significant differences in injury score, internal elastic lamina, lumen area, and restenosis rate were found. However, the fibrin score was more significantly decreased in the ion beam-implanted group (2.5±0.15) than in the bare metal stent group (1.8±0.31, <I>n</I> =10, <I>p</I> <I><</I> 0.05). Taken together, ion beam implantation may be an efficient accessorial tool for preventing in-stent restenosis and in-stent thrombosis.</P>

스키 리조트 이용자의 여가갈등에 관한 연구

한우진(Woo Jin Han),이장희(Jang Hee Lee),여인성(In Sung Yeo) 한국여가레크리에이션학회 2005 한국여가레크리에이션학회지 Vol.29 No.-

Although various studies concerning leisure conflict have been conducted in the U.S, there is little research in this area for Korean. There are many both unasked and unanswered questions in the experience of leisure conflict between or among various leisure activity group. Therefore, an attempt to understand the experience of leisure conflict in ski resort between skier and snowboarder may provide new insights into the nature of leisure conflict of Korean. The purpose of this study was to examine differences of leisure conflict by demographic variables and investigated effect of user’s characteristics in leisure conflict between skier and snowboarder.For this study, 482 participants were selected from 2 ski resorts located in Kangwon Province for one month from January 15th to February 15, 2005, using the convenience sampling method. For the data analysis SPSS 12.0 for Windows version was utilized. The hypothesis tests were conducted with independent t-test, one-way ANOVA, and Multiple Linear Regression to solve problems of the study. On the basis of the results, the conclusions were drawn as follows; 1. There are differences in leisure conflict between or among skier and snowboarder’ demographic characteristics(gender and age group) 2. Leisure conflicts of skier are effected by user’s background in both in-group and out-group. 3. Leisure conflicts of snowboarder are effected by user’s background in both in-group and out-group.

수령독재 하에서 권력과 이권을 둘러싼 갈등 동학 그리고 장성택 숙청

박형중 ( Hyeong Jung Park ),최대석 ( Dae Seok Choe ),김학성 ( Hank Sung Kim ),박영자 ( Young Ja Park ),장인숙 ( In Suk Jang ) 북한연구학회 2014 北韓硏究學會報 Vol.18 No.1

수령독재 하에서는 수령 지위를 차지하고자 하는 권력 투쟁은 존재하지 않는다. 그러나 수평적으로 주요 기관과 엘리트 개인의 권력과 이권의 지분을 확대하기 위한 경쟁이 존재한다. 이러한 경쟁은 수령에 대한 ‘충성경쟁’이라는 외피를 갖는다. 권력 세습 기간 동안 이러한 경쟁이 현저히 증가한다. 권력 세습은 수령독재가 기반하는 통치연합을 재편성하는 과정이기 때문이다. 김정일에서 김정은으로의 권력 세습 과정에서 기관과 엘리트 사이에 권력 및 이권 관련경쟁에서 두 가지가 두드러지게 나타났다. 그 하나는 권력 세습 과정에서의 주도적 세력이 되고자 하는 경쟁 즉 후견권을 둘러싼 경쟁이다. 그 다른 하나는 기관별로 권력과 이권의 지분을 확대하기 위한 경쟁이다. 장성택은 이 두 가지 경쟁에서 모두 주역이었다. 그의 숙청도 이와 관련되어 있었다. Under the Suryong dictatorship, by definition, there is no political completion for Suryong`s status. There are, however, horizontal competitions to expand power and interest carried out by major power organizations and elites. Apparently they are loyalty competition devoted to the Suryong. During the power succession, as the ruling coalition is reconstructed, they intensify themselves. Two features have been pronounced during the hereditary succession from Kim Jong-il to Kim Jong-un in regard to competition for power and interest among power organizations and elites: the one is the competition for regency, i.e. to advance oneself as the dominant force in the promotion of the power succession; the other is the competition for increasing share of power and interest by power organizations and elites. Jang Sung-taek has stood in the center of these two competitions and he was purge thereof.

In-situ Test of ZigBEE System for Wireless Vibration Monitoring

Seo Il Chang(장서일),HyeSung Jeon(전혜성),In Jang Hwang(황인장),Sung-Hwan Jung(정성환) 한국소음진동공학회 2016 한국소음진동공학회 학술대회논문집 Vol.2016 No.10